So I found this thread that tested various products:

https://www.mtbr.com/threads/anti-co...1073581/page-6

Frame Saver did not do well. Fluid Film and WD-40 Specialist Long-Term Corrosion Inhibitor came out on top.
Apparently Fluid Film smells really bad so I am not wanting to use it. I am little concerned about any of these products harming the paint.
Maybe I don't need to use anything as I read that steel frames really do not really rust from the inside, but water can possibly get in around the seat post if there are gaps.
I live in San Diego so the weather is pretty mild, no salt on the roads and I never ride in the rain.
Bike will be stored in the garage and I live a few miles from the ocean.
I had six different steel frame bikes back in the 1970 / 1980s and never had a problem with rust except on the outside of the frame.
I am wondering if Frame Saver is a solution to a non-problem?